Here's the best chimera I have ever seen. On this
one half the bloom is the normal blue-white and the other is pure blue. One
other bloom on the same stem has half of one fall and std blue.

Song of Norway is basically a blue with one
or more copies of a dominant white gene which supresses the full expression of
the blue. However very rarely, in part of a bloom or stem this gene fails to
work allowing the underlying colour to be seen. This is called a
chimera.